I did this for my Mom with some Santa pics she had done over the years on a fine count loose weave like that. I zigzagged the edges to keep from fraying, then used a woven horsehair type interfacing fused on the back. I wasn't as stiff as I expected it to be. She is using it as a wall hanging too, which is okay with that much body. The only interfacing I have ever known to hold it's stiffness after washings is the bulky weight Pellons used for waistbands and shirt or lapel collars.